The present study evaluated the vertical marginal gap distance of recently introduced monolithichighly translucent zirconia crowns compared to veneered translucent zirconia with two different finish lines (shoulder and deep chamfer).A total of twenty four (n=24) crown samples were constructedfrommonolithic highly translucent zirconia (n=12) and veneered translucent zirconia (n=12) using CAD/CAM system on specially designed stainless steel die (8mm cervical diameter, 6mm occlusogingival height and 15-degree total occlusal convergence).The preparation ended with either:1mm shoulder finish line or 1mm deep chamfer finish line.The crown samples were then divided into two equal groups:Group I: (n = 12)Monolithichighly translucent zirconia (ZirkonzahnPrettau Zirconia).Group II: (n = 12) Veneered translucent zirconia (Zirkonzahn IceZirconia).Each group was then subdivided into two equal subgroups:Subgroup 1: (n = 6) Shoulder finish line.Subgroup 2: (n = 6) Deep chamfer finish line.24 Impressions form the stainless steel dies were made using a cylindrical copper perforated tray, these impressions were then poured into type IV improved dental stone to obtain an exact replica to the stainless steel dies.The stone dies received monolithichighly translucent zirconia crowns (Prettau) (n = 12) and veneered translucent zirconia crowns (ICE Zirconia) (n = 12), with two different finish line designs (shoulder (n=6) and chamfer (n=6)).Veneering of the translucent core was done using the layeringtechnique. After definitive sintering for both groups, the vertical marginal gap distance of all samples was tested by using a stereomicroscope, and the data were tabulated and statistically analyzed.The measurements of the vertical marginal gap distance of chamfer finish line design for MonolithicHighly Translucent Zirconia (FZ) to that of Veneered Translucent Zirconia (VZ) crown group samples showed a highly statistically significant difference between two groups where the recorded mean values were (40.45μm and 19.80μm) respectively at p ≤ 0.05.Table (9) and Figure (35).Also the measurements of the vertical marginal gap distance of shoulder and chamfer finish line designs for MonolithicHighlyTranslucent Zirconia (FZ) crown group samples showed a highly statistically significant difference between two groups where the mean values were (17.27μm and 40.45μm) respectively at p ≤ 0.05.The results obtained in this study showed that the marginal adaptation values were all within the clinical acceptable range, for both finish line designs, the shoulder finish line showed the mean value of17.27μm and 17.40μm for the monolithic and veneered zirconia respectively while for the chamfer finish line the mean was 40.45μm and 19.80μm for monolithicand veneered zirconia respectivelyA 90◦ shoulder finish line showed a superior marginal seal than deep chamfer finish line in zirconia crowns and manually veneered translucent zirconia crowns resulted in a more favorable marginal fit when compared tomonolithic highly translucent zirconia crowns